Application of test kits for water samples to screening contaminated soils for chromium (VI)

To develop a screening method for chromium (VI) in soils, test kits normally used for water samples were applied to the water extracts from two chromium (VI)-contaminated reference soil samples. The chromium (VI) contents determined by water extraction at an ambient temperature and detection by commercial test kits amounted to 71% and 34% of the certified content for sandy loam and clay soil, respectively. The recovery increased to 82% and 59% for respective soil when the extraction was made with a mixed sodium carbonate-sodium hydroxide solution that is employed in the standard method for soil chromium. These results indicate that the extraction with water or alkaline solution combined with chromium (IV)-detection by test kits works as a rapid screening method for chromium (VI) in contaminated soils.